The RAC said the big four supermarkets were making the most profits from petrol – an average of 16p for every litre of unleaded fuel sold in October, and 12p for every litre of diesel. It also said the profit on unleaded was double the average the supermarkets had been making since 2012. In response, Asda told the BBC its prices were around 4p per litre cheaper than the UK average; Tesco, Sainsburys and Morrisons didn’t comment.